Universal contact bar for electric circuits



March 24, 1925. 1,531,138

F. sATTr-:RSTROM UNIVERSAL CONTACT BAR Foa ELECTRIC CIRCUITS Filed OCC.29 1920 MF1 A v 56 56 :o .if

.Patented Mar. 24, 1925.

UNITED STATES FERDINAND sATTnnsrnoM, or IIAsTINes,

PATENT vOFFICE.

MINNESOTA, AssIeNon 'ro MAGNETIC POWER TRANSMITTER COMPANY, 0FFABIBAULT, MINNESOTA, A CORPORATION OF MINNESOTA.

uNIvnnsAI. coN'rAcr BAB. ron-ELECTRIC crnccms.

\ Application led October 29, 1920. Serial N0.420,484.

tain new and useful Improvements in Universal Contact Bars for ElectricCircuits, of which the following is a specification.

This invention relates to improvements in contact means desi edparticularly for use in connection wit a series of electric circuitssuch as are providedwith electrically actuated typewriters, thoughcapable of being used wherever a plurality of electrically controlleddevices are arranged to be actuated from a single battery' orsource.

of electric power or energy.

The present application is in part generic to and in part a continuationof my Patent No. 1,395,599, issued November 1, 1921, for electricalactuating means for ltypewriter type bars and other devices.

It 4is well understood that when an electric current is broken a- Sparkoccurs which corrodes, burns or otherwise ruins'any contact exceptingone made of platinum, thereby making such contact unreliable. Platinumhas been found to be the only metal which will withstand, for a' longperiod of time, the eect produced by the breaking of an electriccurrent.

In devices where many make and break contacts are to be used, as in atypewriter, the number of contacts varying from pos@ sibly 40 to 80, asmay be theA case, the work and expense of supplying a separate pair ofplatinum. contact points for each key is necessarily expensive.

One of the objects of this invention is to make use of. only a singlepair of ContactA points for operating levers, such as type keys,whatever their number ma be, acting with a universal contact formlng barlocated in proper relation tothe other elements of the device.

The invention consists generally in a universal contact bar or connectorarranged in operative relation to a contact point or pair of contactpoints, and a series of operating keys or levers, whereby an electriccircuit may be closed through said pair of contactpoints upon theoperation of any one of sald lkeys or levers.

' In the accompan in drawn formin part of this speciictii, gs g Flgure 1is a plan view of a portion of a typewriter key-board, with my inventionapplied thereto.

Figure 2 is a vertical section of the key-V board showing onearrangement of the universal contact bar or-connectorand showing alsothe connection of the circuits to 'the magnets of an electricallyactuated typewriter.

Figure 3 isa detail illustrating the operation -of the universal contactbar, or connector.

In the drawings, 2 represents a portion of the frame of a typewritermachine, whichv furnishes support for a series of type bars 3, each ofwhich is provided with a suitable typ'e 4. The frame 2 is preferablyprovided with a plate 5 supporting lugs 6 tov which the type-bars 3 arepivoted. The type-bars are arranged to be operated by actuating levers8, each pivoted to a bracket 9 on the frame of the machine and connectedto the type-bar'by a link 10. A connecting member'12 is pivoted to eachof the actuating levers 8 and the position of these members iscontrolled by the armature 21 of the selecting magnet 20. An actuatingorjpower magnet 30 is provided with an armature`29`arranged to actuate auniversal power bar 24.

These parts are arranged substantially as set forth in my said pendingapplication whereby, when t e magnets are energized, the type-bars willbe actuated to impress the type upon paper suitably placed in themachine, substantially las described in my said pending applicatiom Irovide a se ecting magnet 20 for each of t e type-bars and a key-boardis employed having a key, or a key-lever 40, for eac selecting magnet. ASuitable arrangement of key-board with the key-levers 40, each providedwith a suitable key-top 41, is illustrated'in Figures 1 and 2 of thedrawings. As here s vi ed with a suitable frame 38 upon w ich thekey-levers are pivoted by suitable pivotal supports 39.A kThese keys arearranged in any preferred manner.

Arranged beneath the key-levers, and extending transversely thereof is arock shaft own the key-board is ro-v springs 46 are connected to saidcrank arms and to stationary points on the machine 42 mounted insuitable bearings 43, 43. Secured to this rock shaft' preferably nearits end are crank arms 44 supporting or formed integrally with theuniversal contact bar or connector 45. The crank arms preferably extendto the rear of the rock shaft 42 and frame. Suitable stops 44 arepreferably provided to limit the upward movement of the bar 45.v Thesprings 46 tend, at all times, to hold the universal contact bar at theupper limit of its movement, while permitting said bar to be moveddownward when pressure is applied thereto at any point in itslength. V

Arranged beneath each of the key-levers is a contact arm or member 50preferably pivoted to a suitable insulated stationary` support 51 on theframe of the key-board and arranged to, be held in an elevated 'positionby a suitable spring 52. An insulating block 53 is preferably secured tothe under side of each key-lever 40, and the contact arms 50 arenormally held with their upper or forward ends resting against the underside of said insulating block.

Beneath the contact bar 45 is arranged a contact spring or member 54having preferably `a platinum contact point 54 The spring 54'is securedupon a suitable insulating support and is preferably electricallyconnected to a circuit wire extending to the powerniagnet 30, said powermagnet having ground connections at B.

A suitable plate of insulating material 55 is preferably arranged uponthe frame of the key-board. On this plate the supports 51 for the.contact arms l50, the bearings 43 for vthe rock shaft 42, supportingthe universal contact bar 45, and the contact spring or member 54, areal1 supported.

Each of the contact arms 50 is in electrical connection, through acircuit wire C, with the corresponding selecting magnet 20, and eachselecting magnet has a ground connection C. Supported upontheiinsulating plate 55 beneath the contact spring or member 54 is asecond contact` spring or member 56 also provided with a platinumcontact point 56 adapted to make contact with the platinum 54 on thespring 54, when said last named spring is depressed by the universalcontact bar.

The spring 56 is connected to an electric circuit wire D which isgrounded at D', and

is connected to a suitable battery E.

It will be seen that'with this arrangement 'of the universal contact baror connector and the co-o erating elements provided in the key-boar anynumber of circuits may be closed with a single pair of contact springs,and, therefore, it is ,only necessary to provide -a single pair .ofcontact points for any number of circuits. I

prefer this construction, but these air gaps A are not necessary to theoperation of the device. The upper surface of the bar 45 may be normallyin contact with the under surface of all of the contact arms 50, and itsunder surface normally'in contact with the spring .54. In this case theonly air gap is between 'the contact points 54 and 56. When any one ofthe key-levers is depressed the corresponding arm 50 forces the bar 45downward forming an air gap between the bar 45 and all of the other arms50, and pressing the two contact points 54 and 56 of the springs 54 and56 into electrical contact with each other.

The operation of the entire mechanism vwill be more fully seen byreference to my.

closing arms, and means for bringing any one of said arms into contactwith said bar or connector to move the sameinto engagement with saidcontact spring for the purpose of vclosing lan electric circuit,

[through the selected and operated arm.

2. A universal contact bar or connector,

vin 'combination with a circuit closing mem-l ber, and a series ofoperating arms, each arranged to engage said bar, and move the same intoposition to close an electric circuit through said 'contact member andthe operated arm.

3. A universal contact bar or connector in combination with a circuitclosing member, and a series of operating arms or members by which saiduniversal bar may be moved to engage said contact member and close acircuit through said contact members, the universal bar and the operatedarm. y

4. The combination, with a plurality of electric circuits, and a sourceof electrical energy for all of said circuits, of a universal electricconnector and a plurality of bars each movable into contact-with theconnector tric energy.

5. The combination, with a plurality of'130 electric circuits, and asource of electrical energy common to all of said circuits, and providedwith a single contact device, of a universal circuit connectorV meansmovable to be first connected to said connector, and

thereafter by further movement to be brought into electrical connectionwith said contact devices.`

6. The combination, with a plurality of electric circuit conductors, asource of electric energy, and a contact device connected therewith, ofa `universal contact bar, means for first establishing an electric:contact between any selected circuit conductor, and said contact bar,and thereafter establishing an electrical contact between said bar andsaid contact device.

7. The combination, with a plurality of electric circuit conductors, abattery, an electric contact device connected with said battery, of auniversal contact bar or connector, an actuating lever Afor each circuitconductor, having an electrical connection with said conductor, andarranged to rst engage said contact bar and thereafter to move said barinto electrical connection with said contact device. A

8. The combination, with a plurality of electric circuit conductors, asource of electric energy, and an electric contact device connectetherewith,` of a universal electric p connector, and means connectedwith each of said circuit conductors and arranged to engage and movesaid universal connector and, to establish an electric connectionbetween said connector and said contact device, whereby a circuit may beclosed through any one of said circuit conductors.

9. The combination, with a plurality of electric circuit conductors, asource of electric energy, and au electric `contact device connectedtherewith, of a universal electric connector, and means connected witheach of said circuit conductors for establishin contact with saiduniversalE connector and thereafter producing contact between saiduniversal connector and said contact device. 10. The combination with aplurality of circiuit closing contactlsprings having an electric contactbetweenA the springs, a movable contact bar or connector arranged tocontact with one of said springs to close the contact between thesprings, a' series of independent circuit closing arms, and means forbringing any one of said arms into contact with said bar, or connectorto move the same into engagement with one of said sprin s to close theelectric circuit through the se ected arm.

In witness whereof, I have hereunto set my hand this 15th day of October1920.

FERDINAND SATTERSTROM.

